Printed circuit unit for a camera

ABSTRACT

A printed circuit unit for a camera, comprising 
     A photo-sensing means to measure brightness of an object, 
     An integrated exposure operation circuit means to conduct exposure operation based on the photo-sensing output from said photo-sensing means and other exposure factors for determining a proper exposure value (an exposure time value or an exposure aperture value), 
     An electro-optical display means to digitally display in an optical manner the exposure value (the exposure time value and/or the exposure aperture value) within a field of view finder of the camera, and 
     A flexible printed circuit sheet having electrically conductive paths to electrically connect said photo-sensing means and said display means to said exposure operation circuit means, 
     And in said printed circuit unit, said photo-sensing means, said display means and said integrated exposure operation circuit means are mounted on said flexible printed circuit sheet, and an opening is formed at a part of said printed circuit sheet to allow the image light beam from a photo-taking lens system to impinge on a film, 
     And said printed circuit unit is so made that said photo-sensing means and said display means are so placed as closely facing a part of the optical assembly of the camera, and the opening at said printed circuit sheet matches with a photographing picture frame of camera, so that it is mounted in a very limited space within said camera.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a printed circuit unit for a camera andparticularly to a printed circuit unit having various functionalelements (circuit paths or circuit chips) for exposure measuring,exposure operation and exposure value display, etc., mounted on aflexible printed circuit sheet.

2. Description of the Prior Art

Recently a camera employs more and more electronics technology, and ithas become already general practice to conduct not only exposuremeasuring and operation of appropriate exposure based on the result ofsaid measuring but also the control of exposure action thereof in anelectric manner, and particularly nowadays for instance there is suchsystem that a light emitting element such as LED (Light Emitting Diode)etc. is used so that exposure value can be digitally displayed in anelectro-optical manner within a field of view finder. But in this kindof camera electric circuit devices which have become more and more largeand complicated are built in the same in highly dense manner togetherwith a number of electric circuit parts.

On the other hand, since a camera is a very equipment for whichcompactness in size and light weight are very valuable and importantfeature, various mechanical devices and optical assemblies which havealready been made to have compact size are housed inside the housingthereof in a highly dense manner, thus only very small furtherscatteredly formed extra spaces are left for the above mentionedelectric circuit systems, such as the space between an upper cover partof camera and mechanical parts or optical assemblies and the spacebetween a bottom cover part of camera and mechanical parts. Therefore,in order to effectively utilize said very limited space, nowadays suchefforts have been made to provide almost all of the above mentionedelectric circuit systems in ICed (Integrated Circuited) manner as muchas possible together with a vital core circuit part within the abovementioned limited space being scatteredly positioned except suchelectric parts as direct input and output interfaces for each ofmechanical assemblies and optical assemblies, for example, variousresistors to set film sensitivity, exposure time value or exposureaperture value, photo-sensing element, various switches, electro-magnetto control the action of shutter device or diaphragm device, and adisplay means to display exposure value, etc. In this case, further newand improved positional arrangement of each of said scatteredlypositioned IC circuit parts and electric parts together with the form orarrangement of the electrical connections between said parts will berequired.

Especially, as has been mentioned above, when the brightness of anobject is measured by a photo-sensing element and the exposure value(the exposure time value or the exposure aperture value) to obtainappropriate exposure is operated based on the result of saidmeasurement, further said exposure value (exposure time and/or aperturevalue) is optically displayed within a field of view finder by anelectro-optical display element for example a light emitting element, aliquid crystal element, etc., since said photo-sensing element anddisplay element are to constitute direct input and output interfaces forthe optical assembly of camera, they need to be positioned closelyfacing to a part of the optical system of camera for example the viewfinder optical system. And in this case, the position at which each ofsaid photo-sensing element and display element is placed will havelimitations depending on the positional layout of the optical assemblyof camera in view of the requirements for satisfying such conditionsthat the display information light beam from the display element mustnot impinge on the photo-sensing element to impair the photo-sensingaccuracy, and the photo-sensing element must be able to measure objectbrightness accurately, further the display information by the displayelement must be visually recognized within the field of view finderwithout any difficulties, etc.

On the other hand, an exposure operation circuit to determineappropriate exposure value based on the photo-sensing output from thephoto-sensing element, even if they are formed by IC into one or more ICchips, is ordinarily mounted for example using the space between acamera bottom cover and mechanical part or the space between a cameraupper cover and a penta-prism constituting the view finder opticalsystem of camera, from the view point of convenience for adjustmentthereof and for built-in operation thereof into a camera, therefore,there is a problem for wiring for electrical connection between theexposure operation circuit and the photo-sensing element and displayelement. If thus scatteredly positioned IC circuit parts and each ofelectric parts are connected by conventional lead wires, especially itswiring operation becomes very complicated and assembly work of camerabecomes very difficult, further such fear as an increase in troubles bydamage on the lead wire or failure in connection, etc. is generated,further there will be such disadvantages that the positional layout ofvarious mechanical assemblies and optical assemblies of camera will begreatly influenced by said complication, difficulty and fear. Thus afurther improved set up and positional arrangement for electric circuitsystems are strongly desired to satisfactorily eliminate thesedisadvantages.

SUMMARY OF THE INVENTION:

The present invention is made in view of the above and has an object toprovide such more improved and unique arrangement as totally eliminatingsaid disadvantages as the set up and positional arrangement of electriccircuit systems, which performs various function mentioned below, whenobject brightness is measured by a photo-sensing element and appropriateexposure value is determined by an exposure operation circuit meansbased on the result of said measurement and said determined exposurevalue and/or pre-set exposure value are displayed optically within theview finder field of camera by an electro-optical display means.

Another object of the present invention is to provide such furtherimproved set up and arrangement of electric circuit systems that the setup and positional arrangement of the above mentioned electric circuitsystems performing the above mentioned function are made small indimension by forming the vital core circuit part thereof with IC and thewiring between said IC circuit part and said photo-sensing means andsaid display means is reduced, and at a same time the positional layoutof various mechanical assemblies and optical assemblies at an inside ofcamera is made easy, further the complications in positional layout ofsaid electric circuit systems within camera are satisfactorilyeliminated.

Further another object of the present invention is to provide animproved set up and arrangement of said electric circuit systems whenwhile TTL photo-sensing is done in a single lens reflex camera, theexposure value information is digitally displayed in an electro-opticalmanner within a field of view finder of camera, particularly beingsuited to the positional arrangement and layout of the view finderoptical assembly in said camera.

For achieving said objects in the present invention such set up andarrangement of the electric circuit systems are proposed that oneprinted circuit unit is constituted by a flexible printed circuit sheethaving electrically conductive paths to electrically connect thephoto-sensing means, an integrated exposure operation circuit means, anda digital display means, further to electrically connect saidphoto-sensing means, the display means and other electric circuit partsto the integrated exposure operation circuit means, wherein saidphoto-sensing means, the display means and the integrated exposureoperation circuit means are mounted on said flexible printed circuitsheet, and at a same time an opening is formed in said flexible printedcircuit sheet to allow the image light beam from a photo-taking lenssystem to reach a film, so that said photo-sensing means and the displaymeans are closely facing to the view finder optical assembly of cameraand said opening in the flexible printed circuit sheet matches with thephotographing picture frame of camera, thus these parts can be mountedwithin the limited space in said camera.

Further another object of the present invention is to provide animproved arrangement as the electric circuit system performing the abovementioned function is mounted to a view finder adaptor being so made ascan be mounted to and dismounted from the camera body, being suited tothe positional arrangement and layout of the view finder opticalassembly in said finder adaptor.

To achieve said objects such arrangement of the electric circuit systemsis proposed in the present invention that one printed circuit unit isformed by a flexible printed circuit sheet having electricallyconductive paths and terminals to electrically connect the photo-sensingmeans, an integrated exposure operation circuit means, the digitaldisplay means, further to electrically connect said photo-sensing means,the display means and other electric circuit parts to the integratedexposure operation circuit means, wherein said photo-sensing means, thedisplay means and the integrated exposure operation circuit means aremounted on said flexible printed circuit sheet, and at a same time acut-out part is formed in said flexible printed circuit sheet to allowthe light beam passing through the view finder optical assembly at saidfinder adapter to be exited out of said view finder, so that saidphoto-sensing means and the display means are closely facing to the viewfinder optical assembly of said finder adapter and said cut-out part inthe flexible printed circuit sheet matches with the view finder field ofsaid finder adapter, thus such arrangement is proposed that said partscan be mounted to the limited space of said finder adapter in the abovementioned manner.

Still another object of the present invention is to provide an electricdevice performing the function of exposure setting together with thefunction of measuring exposure, operation of exposure based on theresult of said measurement and electro-optical display of said operationresult, in a form of one unit being formed by IC's as much as possible,together with other objects of the invention.

And to achieve said object such printed circuit unit is proposed in thepresent invention that further, a physico-optical shutter for example ashutter consisting of liquid crystal layer is mounted on said flexibleprinted circuit sheet having the same faced to the above mentionedopening on said printed circuit sheet in said printed circuit unit sothat said shutter is controlled based on the output from said exposureoperation circuit.

Further objects and characterizing features of the present inventionwill be made apparent from the description made in reference to theattached drawings given below.

BRIEF DESCRIPTION OF THE DRAWINGS

Now explanations will be made on the drawings on some examples of thepresent invention.

FIG. 1 is an external oblique view to show a set up of a first exampleof a printed circuit unit according to the present invention.

FIG. 2 is a front view of the printed circuit unit shown in FIG. 1.

FIG. 3 is a block diagram to show the arrangement of circuits in theprinted circuit unit shown in FIG. 1 and FIG. 2 and the manner ofconnections of said circuits in a camera.

FIG. 4 is a schematic explanatory drawing to show a layout in a singlelens reflex camera as the printed circuit unit shown in FIG. 1 and FIG.2 is mounted to said camera.

FIG. 5 is a schematic explanatory drawing to show a manner of display ofexposure value information within a field of a view finder of camera.

FIG. 6 is an external oblique view to show a set up of a second exampleof a printed circuit unit according to the present invention.

FIG. 7 is a block diagram to show a set up of the circuits in theprinted circuit unit shown in FIG. 6 and a manner of connections of saidcircuits in a camera.

FIG. 8 is a schematic explanatory drawing to show a layout in a singlelens reflex camera as the printed circuit unit shown in FIG. 6 ismounted to said camera.

FIG. 9 is a graph to show a relationship between a driving time of thephysico-optical shutter shown in FIG. 6 and FIG. 7 and an effectiveexposure time obtained thereby.

FIG. 10 is an external oblique view to show a set up of a third exampleof a printed circuit unit according to the present invention.

FIG. 11 is an external oblique view to show a set up of a fourth exampleof a printed circuit unit according to the present invention.

FIG. 12 is a schematic explanatory drawing to show a positional layoutof especially a photo-sensing element and a display element in a viewfinder optical system of a single lens reflex camera when the printedcircuit unit shown in FIG. 11 is mounted to said camera.

FIG. 13 is an external oblique view to show a set up in a case when aprinted circuit unit according to the present invention is so made ascan be mounted to a view finder adapter which is freely mountable to ordismountable from a camera body, as a fifth example of said unitaccording to the present invention.

FIG. 14 is a schematic explanatory drawing to show a manner of layout ofthe printed circuit unit shown in FIG. 13 at a view finder adapter as itis mounted to said adapter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First, explanations will be made on a first example of a printed circuitunit according to the present invention. What is shown as 1 in FIG. 1 isa flexible printed circuit sheet made of heat-resistant insulating typeof synthetic resin material of polyester type or of polyimide type,etc., and an opening 1a being larger than a photographing picture frameof camera if formed at a position corresponding to said picture frame ata portion of said sheet, further electrically conductive paths 2 areformed by printing on the surface of said sheet.

What is shown as 3 is an electro-optical display means which houses incompact manner light emitting elements 4a and 4b (for example LED-LightEmitting Diode, etc.) of seven segments for exposure value display anddecoder-driver circuits 5a and 5b to drive said light emitting elements4a and 4b within one insulating type casing 6 forming the same in apackaged manner, wherein the light emitting element 4a is applied toelectro-optically display exposure time value while the light emittingelement 4b is to display exposure aperture value within a view finderfield of a camera, also the decoder-driver circuit 5a is used to drivethe light emitting element 4a, while the decoder-driver circuit 5b isused to drive the light emitting element 4b.

Also as shown in FIG. 3 said light emitting element 4a consists of adisplay part 41 for displaying fraction values and display parts 42 to45 for displaying four figures, while the light emitting element 4bconsists of two displays parts 46 and 47.

And said decoder-driver circuit 5a consists of such number ofdecoder-drivers 51 to 55 as corresponding to the number of said displayparts 41 to 45 of the light emitting element 4a, wherein especially thedecoder-driver 51 to drive the fraction value display part 41 is so madeas driving said fraction value display part 41 only when the informationrecorded in a registor 7 displays exposure time value of below 1/2second (that is shorter than 1/2 second).

What is shown as 8 is a photo-sensing element to measure brightness ofan object and is placed near said display means 3. What is shown as 9 isan exposure operation circuit of analogue type to conduct exposureoperation based on the photo-sensing output from said photo-sensingelement 8, the film sensitivity value provided by a variable resistorVR1 (shown in FIG. 2, FIG. 3), and the preset exposure aperture valueprovided by a variable resistor VR2 (shown in FIG. 2, FIG. 3, FIG. 4)for determining the proper exposure time value, and is made with IC's asmuch as possible except for example a condensor C for memory, etc.

What is shown as 10 is an A-D (Analogue-Digital) converter to convertthe analogue output from said exposure operation circuit 9 into forexample digital signal of 4 bit, and said register 7 records the outputof said A-D converter 10. What is shown as 11 is an A-D converter toconvert the analogue signal (preset exposure aperture value) provided bysaid variable resistor VR2 into digital signal of 4-bit and to give thesame to said decoder-driver circuit 5b, and what is shown as 12 is aclock pulse generator to provide clock pulse for said A-D converters 10and 11. Also general purpose type of circuit chips being made with IC'scan be used as said registor 7, A-D converters 10, 11 and clock pulsegenerator 12.

What is shown as 13 is a masking plate to prevent the displayinformation light beam from said light emitting elements 4a and 4b fromimpinging into said photo-sensing element 8 to deteriorate thephoto-sensing accuracy, and has an opening 13a corresponding to saidphoto-sensing elements 4a and 4b, an opening 13b corresponding to saidphoto-sensing element 8, and a light-shielding part 13c positionedbetween said openings 13a and 13b, further is fixed on said displaymeans 3 by such method as adhesion etc. when the printed circuit unit isassembled.

When the printed circuit unit consisting of the above mentionedcomponent elements is assembled, each of said circuit paths is mountedon the flexible printed circuit sheet 1 and is electrically connected bysuch means as soldering, etc. utilizing conductive paths 2 formed onsaid printed circuit sheet 1, and said manner of connection is shown inFIGS. 2 and 3.

That is, the decoder-driver circuits 5a, 5b in said display means 3 areconnected respectively to the register 7 and the A-D converter 11, whilethe A-D converter 10 is connected to the register 7 and the exposureoperation circuit 9. Also the photo-sensing element 8 is connected tothe exposure operation circuit 9 and the clock pulse generator 12 isconnected to the A-D converters 10 and 11.

And the printed circuit unit thus assembled is mounted in a camera usingthe space between a camera casing body 15 and a shutter 16 as an examplebeing bent along the line A--A depending on the limited space within asingle lens reflex camera as shown in FIG. 4, in such manner that theopening 1a in the flexible printed circuit sheet 1 matches with anopening 15a formed at a part of said camera casing body 15 and thephoto-sensing element 8 matches with a prism 25 for photo-sensing in aview finder optical system of camera, further the light emittingelements 4a and 4b match with a reflective prism 26 for display at theview finder optical system of camera, wherein various electrical partsscatteredly positioned within said camera are electrically connected bysuch methods as soldering, etc. to each of circuit paths in said printedcircuit unit utilizing the conductive paths 2 formed on said printedcircuit sheet 1. That is, as shown in FIGS. 2 and 3, the above mentionedvariable resistor VR1 for setting film sensitivity is connected to theexposure operation circuit 9, also the variable resistor VR2 for settingexposure aperture value is connected to the exposure operation circuit 9and the A-D converter 11 together with a voltage dividing resistor R.

Also what is shown as E is a power source and is connected to theexposure operation circuit 9 and clock pulse generator 12 together witha power source switch S1. Also what is shown as S2 is a memory switchactuated by a release button not being shown in the drawing and isconnected to a memory condensor C at the exposure operation circuit 9.Also what is shown as 14 is a conventionally known shutter controlcircuit and is connected to the above mentioned exposure operationcircuit 9 by a change over switch S3 to change over the exposure actionmode between an automatic control mode "A" and a manual control mode"M," when said switch S3 is changed over to "A."

Also what is shown as S4 is a conventionally known switch for initiatingexposure time counting linked with an opening action of said shutter 16,and what is shown as Mg is an electro-magnet to control a closing actionof said shutter 16, while what is shown as VR3 is a variable resistor tomanually set the exposure time value and is connected to a shuttercontrol circuit 14 by said switch S3 when said switch S3 is changed overto "M" side. Also in FIG. 4, what is shown as 17 is a photo-taking lenssystem and what is shown as 18 is a diaphragm provided within said lenssystem, while what is shown as 19 is a preset ring to preset theexposure aperture value, wherein the above mentioned variable resistorVR2 for setting the exposure aperture value is operatively connected tosaid preset ring 19 to provide such electric signal as corresponding tothe exposure aperture value preset by said preset ring 19 to the abovementioned exposure operation circuit 9 and A-D converter 11.

What is shown as 20 is a connectionally known movable reflex mirroraxially supported by an axle 20a in a rotatable manner, and what isshown as 21 is a focusing plate, while what is shown as 22 is acondensor lens having an obliquely set semi-transmitting plane 22aformed at its central part, wherein the above mentioned photo-sensingprism 25 is provided at such position as closely facing the edge of saidcondensor lens 22 in such manner as having the light beam reflected fromsaid semi-transmitting plane 22a impinge into said photo-sensing element6.

What is shown as 23 is a penta prism, and what is shown as 24 is an eyepiece lens, wherein said reflective prism 26 for display has the displayinformation light beam from the light emitting elements 4a and 4bimpinge into said penta prism 23 and is so positioned as closely facingthe bottom plane of said penta prism 23.

What is shown as F is a film and what is shown as 27 is a back cover ofa camera and what is shown as 28 is a pressing plate to hold film down.Also as the above mentioned printed circuit unit is mounted to a camera,the light shielding part 13c of the masking plate 13 is positionedbetween the photo-sensing prism 25 and the reflective prism 26 fordisplay, thereby such fear is effectively eliminated that the displayinformation light beam from the light emitting elements 4a and 4bimpinges into the photo-sensing element 8 to impair the photo-sensingaccuracy.

Next, explanations will be made on the action of the printed circuitunit so provided in a camera as mentioned above together withphoto-taking action of camera referring particularly to FIG. 3. First,when the power source switch S1 is placed in ON state in a state thatthe variable resistor VR1 is set in accordance with the sensitivity ofthe film F used and any exposure aperture value is selected by thepreset ring 19, the exposure operation circuit 9 and the clock pulsegenerator 12 will start their action.

That is, first the exposure operation circuit 9 conducts exposureoperation based on the film sensitivity information provided by thevariable resistor VR1, and the exposure aperture value informationprovided by the variable resistor VR2 linked with the preset ring 19,further the object brightness information provided by the photo-sensingelement 8, to determine proper exposure time value, thus outputting suchanalogue signal as corresponding to said exposure time value to the A-Dconverter 10 (here, at this time if the switch S3 is changed over to "A"as shown in the drawing that is if the exposure action mode is set at anautomatic control mode, the analogue signal at this time will be alsogiven to the shutter control circuit 14).

On the other hand at this time the clock pulse generator 12 will outputclock pulse to the A-D converters 10 and 11.

By this, first the A-D converter 10 digitally converts the analogueoutput from the exposure operation circuit 9 into the digital signal of4-bit based on the clock pulse given by the clock pulse generator 12,then gives the same to the registor 7, thereby the decoder-drivercircuit 5a drives the display parts 41 to 45 at the light emittingelement 4a respectively depending on the information content recorded atsaid registor 7, thus finally the proper exposure time value determinedby the exposure operation circuit 9 will be digitally displayed in anelectro-optical optical manner within a field of view finder by saidlight emitting element 4a.

Therefore, at this time, if the exposure action is set at the manualcontrol mode, that is if the switch S3 is changed over to "M" side,proper exposure time value can be manually set at the shutter controlcircuit 14 by adjusting the variable resistor VR3 based on the exposuretime value information displayed within the view finder field by saidlight emitting element 4a.

On the other hand at this time, the A-D converter 11 converts theanalogue signal provided by the variable resistor VR2 into digitalsignal of 4-bit based on the clock pulse outputted from the clock pulsegenerator 12, and gives the same to the decoder-driver circuit 56,thereby said decoder-driver circuit 56 drives the display parts 46, 47at the light emitting element 4b, thus finally the exposure aperturevalue being preset by the preset ring 19 will be digitally displayed inan electro-optical manner within the view finder field by said lightemitting element 4b.

The state of display of exposure value at this time within the viewfinder field of camera by the display means 3 will be as shown in FIG.5.

Now in said drawing, the exposure aperture value preset by the presetring 19 is "F 5.6" and the proper exposure time value at this time is"1/1000 (sec.)."

When a release button not shown in the drawing is pressed in this state,first, the switch S2 for memory is actuated, thereby the above mentionedproper exposure time value will be memorized by the memory condensor Cin the exposure operation circuit 9 (therefore, even when the reflexmirror 20 is retreated to outside of photographing light paththereafter, thereby the amount of incident light into the photo-sensingelement 8 varies and the output of said photo-sensing element 8 varies,the display state by the light emitting element 4a will not be changedat all, thus the above mentioned display of proper exposure time valuewill be continued as it is.

And after that, at a same time when the reflex mirror 20 is retreated tooutside of photographing light path by further depression of the releasebutton, the diaphragm 18 is stopped down to the exposure aperture valuepreset by the preset ring 19 by a conventionally known diaphragm drivingmechanism, then as the shutter 16 is released, the switch S4 forinitiating counting is actuated in an association therewith, thus theshutter control circuit 14 performs the counting of exposure time basedon the exposure time information provided by the exposure operationcircuit 9 (to be exact by the memory condensor C within said circuit 9)when the switch S3 is changed over to "A" side, or based on the exposuretime information set by the variable resistor VR3 when the switch S3 ischanged over to "M" side, and the electro-magnet Mg is energized (ordeenergized) after completion of said counting of exposure time to closethe shutter 16.

Photographing is done in the manner mentioned above.

Next, explanations will be made on a second example of the printedcircuit unit according to the present invention, wherein the printedcircuit unit in this second example differs from the above mentionedprinted circuit unit in the first example, first in such feature that aphysico-optical shutter containing for example a liquid crystal layer ismounted at a position corresponding to the opening 1a of the flexibleprinted circuit sheet 1, and in such feature that a control circuit tocontrol said shutter is housed within one casing together with allcircuit parts in the first example for forming the same in packagedmanner, further in such feature that a battery box to house a powersource battery for said circuit paths is mounted on the printed circuitsheet 1.

Therefore in the explanations of this second example, such componentelements as duplicating with those in the printed circuit unit in thefirst example will be identified with same numbers or symbols as in saidfirst example, and duplicating explanations will be omitted as long asnot hindering the explanations of the second example.

First in FIG. 6, what is shown as 29 is an automatic exposure controlunit performing all functions for measuring exposure, exposure valuedisplay and exposure control, and said control unit 29 has such set upas shown in FIG. 7 that the above mentioned light emitting elements 4aand 4b, the decoder-driver circuits 5a and 5b, the register 7, thephoto-sensing element 8, the exposure operation circuit 9, the A-Dconverters 10 and 11, the clock pulse generator 12 and the shuttercontrol circuit 30 which is used for controlling a physico-opticalshutter to be described later and is formed with IC's as much aspossible except for example a condensor for time constant, etc. arehoused compactly in one insulating casing 31 and is formed in a packagedmanner.

What is shown as 32 is terminal group to connect said unit 29 to theconductive paths of the flexible printed circuit sheet 1. What is shownas 33 is an electric shutter of physico-optical type made by filling thespace formed by two polarization plates 34a, 34b having transparentelectrodes 36a, 36b and an insulating type spacer 35, with liquidcrystal 37 of field effect type, and said electric shutter 33 is mountedon said printed circuit sheet 1 in such manner as covering said opening1a of said printed circuit sheet 1 as the printed circuit unit isassembled, then said electrodes 36a and 36b are connected to theconductive paths 2 formed on the printed circuit sheet 1 respectively.

Said electric shutter of physico-optical type means a shutter to controlthe incidence of the light beam onto film plane utilizing suchcharacteristics as having optical properties varies by having externalenergy such as electric field, magnetic field, heat, etc. of suchmaterial as utilizing Faraday effect or crystal of field effectactuation type or of dynamic scattering type, or utilizing magneticpower material. This example uses a liquid crystal of the field effecttype.

Also said shutter control circuit 30 consists of an alternating voltagegeneration circuit 30a to impress alternating voltage of 5 volts ontosaid shutter 33 and a switching circuit 30b to determine the voltageimpressing time onto said shutter 33 based on the output from saidexposure control circuit 9 for controlling said alternating voltagegeneration circuit 30a, wherein said switching circuit 30b is connectedto the exposure operation circuit 9.

What is shown as 38 is a battery box to house the power source battery Efor said unit 29, and is mounted on the above mentioned printed circuitsheet 1 as the printed circuit unit is assembled, and is connected tothe conductive paths 2 formed by printing on said printed circuitsheet 1. What is shown as 39 is an opening and closing cover provided ata bottom part of the camera casing body 15 for loading the battery Efrom outside of camera into said box 38 and for taking out the same fromsaid box 38.

A manner in which the printed circuit unit consisting of the abovementioned component elements is mounted at a single lens reflex camerais shown in FIG. 8 and a manner of electric connection between variouselectric parts being scatteredly positioned in said camera and saidprinted circuit unit is shown in FIG. 7, wherein the manner of themounting and of connection in this case are virtually same as the caseof said first example as being apparent by referring to FIG. 3 and FIG.4, therefore detailed explanations thereof will be omitted.

Now in FIGS. 7 and 8, what is shown as S5 is a switch for shuttertriggering being actuated as said mirror 20 is completely retreated tooutside of photo-taking light path in an association with said reflexmirror 20, and is connected to said shutter control circuit 20 as in theabove mentioned change over switch S3.

Also the movable reflex mirror 20 is so made as being returned to aposition shown in FIG. 8 when the depression of release button isreleased or in an association with the film wind up action.

Next, explanations will be made on the action of the printed circuitunit having the above mentioned set up together with the action ofcamera.

First, when the power source switch S1 is closed after the filmsensitivity and exposure aperture values are set respectively variouscircuit parts function similarly in the case of the above mentionedExample 1, the preset exposure aperture value is digitally displayedwithin the view finder field by the light emitting element 4b, while theproper exposure time value is also so displayed by the light emittingelement 4a.

Therefore, when manual exposure control is desired, proper exposure timevalue can be manually set at the shutter control circuit 30 by adjustingsaid variable resistor VR3 according to the proper exposure time valuedisplayed by the light emitting element 4a in a state in which theswitch S3 is changed over to "M" side and the variable resistor VR3 isconnected to the shutter control circuit 30.

When a release button not shown in the drawing is depressed in thisstate, after the switch S2 is actuated, the switch S5 is actuated at atime when the diaphragm 18 is stopped down by the preset ring 19 to thepreset exposure aperture value and at a same time the reflex mirror 20is retreated to outside of photographing light path, and said mirror 20is completely retreated to outside of photographing light path.

And when the switch S5 is actuated the switching circuit 30b in saidshutter control circuit is actuated to start impressing of alternatingvoltage onto the shutter 33 by the alternating voltage generationcircuit 30a, and at a same time the impressing time of the alternativevoltage required to obtain proper exposure is counted based on theexposure time value, which is determined by the above mentioned exposureoperation circuit 9 when the switch S3 is changed over to "A" side andis set by the above mentioned variable resistor VR3 when the switch S3is changed over to "M" side, and after completion of said counting ofthe impressing time, the impressing of the alternating voltage by thealternating voltage generation circuit 30a is stopped.

Here, the relationship between the impressing time of the alternatingvoltage onto the shutter 33 and the effective exposure time obtainedthereby is as shown in FIG. 9, and for instance, when the impressedvoltage onto the shutter 33 is 5 volts and the impressing time is 5.5milli-seconds, effective exposure time equivalent to about 1/200 secondcan be obtained, also when the impressing time is made as about 80milli-seconds, effective exposure time equivalent to about 1/8 second isobtained.

Next, FIG. 10 is to show a third example of a printed circuit unitaccording to the present invention, wherein circuit parts performingexposure operation and exposure control and circuit parts performing thedisplay of exposure value are mounted separately on the flexible printedcircuit sheet 1 as separate circuit units, and are connected to theshutter 33 and the light emitting elements 4a and 4b respectively by theconductive paths 2 formed on said printed circuit sheet. That is in thisdrawing, what is shown as 61 is a circuit unit housing the exposureoperation circuit 9 and shutter control circuit 30 within one casing 62in a packaged form, and what is shown as 63 is a circuit unit housingsaid decoder-driver circuits 5a and 5b, registor 7, A-D converters 10and 11, and clock pulse generator 12 in one casing 64 in a packagedform, and both units just mentioned are mounted on the flexible printedcircuit sheet 1 and the circuit unit 61 is connected to thephoto-sensing element 8, the shutter 33 and the battery housing box 38by the conductive paths 2 formed on said printed circuit sheet 1, whilethe circuit unit 63 is connected to the circuit unit 61, the displaymeans 40 containing only the light emitting elements 4a and 4b, and thebattery housing box 38.

The details of connections of electric circuit in the printed circuitunit in this third Example are same as what is shown in FIG. 7.

Also what are shown as 65, 66 and 67 are variable resistors for circuitadjustment and are mounted on the printed circuit sheet 1, and thevariable resistors 65 and 66 are connected to the circuit 61 and thevariable resistor 67 is connected to the circuit unit 63, respectivelyby the conductive paths 2. And the above mentioned masking plate 13 ismounted on said display means 40 and the photo-sensing element 8.

Next, FIG. 11, FIG. 12 are to show a modification of the third exampleshown in FIG. 10 as a fourth example of a printed circuit unit accordingto the present invention. And in this fourth example the masking plate13 to prevent the display light beam by the light emitting elements 4aand 4b from impinging into the photo-sensing element 8, as shown in theFirst and Second Examples is not needed.

That is a bent part 1b is provided at the printed circuit sheet 1 insuch manner as being bent just as forming eaves over the photo-sensingelement 8, and the above mentioned display means 40 containing only thelight emitting elements 4a and 4b for display is mounted on said bentpart 1b, and is connected to the circuit unit 63 by the terminal group68 thereof through the conductive paths 2.

Also, while the manner in which said printed circuit unit is mounted ina camera is as shown in FIG. 12, particularly the display means 40 needsto be fixed by an appropriate means. This may be done for example bysuch method as adhering the display means 40 to bottom plane of thepenta prism 23.

Lastly explanations will be made on an example wherein a printed circuitunit can be mounted to a view finder adapter which is so made as freelymountable to and dismountable from a camera body as a fifth example of aprinted circuit unit according to the present invention. In saiddrawings, what is shown as 70 is a flexible printed circuit sheet andhas a first bent part 70a to have the display means 40 containing onlythe light emitting elements 4a and 4b mounted thereon, and a second bentpart 70b to have the photo-sensing elements 8a and 8b mounted thereon,further it is bent depending on a shape of the penta prism 23 built inthe finder adapter.

While said second bent part 70b, especially, is so bent that thephoto-sensing elements 8a and 8b are made to closely face the light beamemergence plane 23a of the penta prism 23, a cut out part 70c is formedat said second bent part 70b so that the light beam emerging out of thelight beam emergence plane 23a of the penta prism 23 especially out ofits central part can impinge into the eye piece lens 24 withoutobstacle. And the above mentioned exposure operation circuit 9 and thecircuit unit 63 for display shown in FIG. 10, FIG. 11 are mounted onsuch portion of the printed circuit sheet 70 as corresponding to "dach"surfaces of the penta prism 23, wherein said exposure operation circuit9 is connected to the photo-sensing elements 8a and 8b and the circuitunit 63, while the circuit unit 63 is connected to the display means 40by the conductive paths 2 formed by printing on said printed circuitsheet 70. Also what is shown as 71 is a terminal group for electricconnection to the camera body and is connected to the conductive paths2.

While the printed circuit unit having the above mentioned set up is bentaccording to the shape of the penta prism 23 as mentioned above and ishoused in the adaptor housing 72, and display means 40, then, is fixedon a reflective prism 74 for display being adjoined to the light beamemergence plane 23a of the penta prism 23, so that the displayinformation light beam generated by the light emitting elements 4a and4b at said display means 40 will be impinged into the eye piece lens 24through a reflective plane 74a of said prism 74. Also what is shown as73 is an insulating type supporting plate to support said terminal group71.

While the finder adaptor thus assembled is mounted to a camera body notbeing shown in the drawing, the electric connection between variouselectric parts provided at said camera body side and said printedcircuit units is made through said terminal group 71, and in a statewherein the finder adapter is mounted to the camera body, for examplecircuits as shown in FIG. 3 are formed therebetween.

As has been explained above, the present invention is to provide oneprinted circuit unit for automatic exposure operation and display, beingmade of one or more circuit means which are made with IC's as much aspossible and perform measurement of object brightness, operation ofproper exposure based on the result of said measurement, andelectro-optical display of the result of said operation, being placed ona flexible printed circuit sheet and being electrically connected byconductive paths formed by printing on said printed circuit sheet,wherein an opening is formed on said printed circuit sheet to allow theimage light beam from a photo-taking lens system to impinge into film,and a cut out part is formed on the same to allow the light beam fromthe view finder optical system to be exited out to outside. Thereforeaccording to said printed circuit unit the complicated wiring operationamong a number of circuit paths or chips being scatteredly positioned ina camera conventionally required will become almost unnecessary, and ata same time it can be mounted utilizing the very limited spaces at theback part and the bottom part within the camera body or the limitedspace within the finder adapter being so made as freely mountable to anddismountable from said camera body, thus such fear can be completelyeliminated as complicating the positional layout of various mechanicalassemblies and optical assemblies within the camera or within the finderadapter.

Also since said printed circuit unit is made as one functional unithaving functions of automatic exposure operation and electro-opticaldisplay of the result of said operation, a conventional camera can havefunctions of automatic exposure operation and display provided theretoinstantly only by having such one functional unit, thus work requiredfor assembly of a camera having function of automatic exposure operationand display can be remarkably reduced.

Furthermore, in the printed circuit unit of the present invention, evenif a photo-sensing means and a display means are positioned very closelytogether, such design is made beforehand to effectively prevent suchsituation that the display information light beam from said displaymeans impinges into the photo-sensing means therefore, even when saidprinted circuit unit is used together with a conventional opticalassembly of camera, such fear as lowering the photo-sensing accuracy bythe display information light beam from the display means can beprevented beforehand.

Also the present invention is to provide such printed circuit unit whichcan have a function of automatic exposure control by a so-calledphysico-optical electric shutter in addition to the functions of theabove mentioned automatic exposure operation and electro-optical displayof the result of said operation, therefore a conventional camera canhave instantly function of automatic exposure control function inaddition to the functions of automatic exposure operation andelectro-optical display of the result of said operation only by havingsuch functional unit which also has the function of automatic exposurecontrol as mentioned above, thus the work in assembly of a camera ofautomatic exposure control type can be remarkably reduced.

Also, while the examples show a case where the above mentioned printedcircuit unit functions as an automatic exposure operation unit of aso-called exposure aperture value preselection type in which properexposure time value is automatically determined by presetting theexposure aperture value, the printed circuit unit of the presentinvention can be so made as functioning as an automatic operation unitof so-called exposure time value preselection type in which properexposure aperture value is automatically determined by presettingexposure time value, depending on how the connections between said unitand the electric parts in a camera are made as it is mounted to thecamera.

What is claimed is:
 1. For a camera which is provided with:photo-takinglens system, view finder optical means, and aperture frame means todefine a photographing picture frame, a printed circuit unitcomprising:(A) photo-sensing means to measure the brightness of anobject to be photographed by said camera, and to produce an electricsignal corresponding to the object brightness, (B) exposure operationcircuit means to determine a proper exposure value based on the outputsignal of said photo-sensing means, and to produce an electric signalcorresponding to a proper exposure value, (C) a display means toelectro-optically display the proper exposure value information based onthe output signal from said exposure operation circuit means, (D)electrically insulating flexible circuit supporting means; saidsupporting means being adapted to be bent into a configuration to fit ina desired space within said camera and having an opening with a size atleast equal to the size of the photographing picture frame defined bysaid aperture frame means, and (E) electrically conductive means beingcarried on said flexible supporting means, said photo-sensing means,said exposure operation circuit means and said display means beingcarried on said flexible supporting means, and said photo-sensing meansand said display means being electrically connected to said exposureoperation circuit means through said electrically conductive means, andsaid supporting means being constructed so that: said photo-sensingmeans is placed at a position to receive a light beam from said objectthrough at least a part of said view finder optical means, said displaymeans is placed at a position having the display informtion light beamdisplay said proper exposure value information and impinge into at leasta part of said view finder optical means, and said opening of thesupporting means matches with said photographing picture frame definedby said aperture frame means, and is mounted in a camera so at least toutilize a restricted space near said aperture frame means.
 2. A unitaccording to claim 1, in which said display means includes:lightemitting means to digitally display the proper exposure valueinformation, digital conversion circuit means to convert the outputsignal from said exposure operation circuit means into a digital signal,said converting circuit means being electrically connected to saidexposure operation circuit means through said conductive means carriedon said flexible supporting means and driving circuit means toelectrically drive said light emitting means based on the digital signalproduced from said digital conversion circuit means, said drivingcircuit means being electrically connected to said light emitting meansand said digital conversion circuit means.
 3. A unit according to claim2, in which said digital conversion circuit means and said drivingcircuit means are made as integrated circuit chips respectively, and atleast a portion of said exposure operation circuit means is made withIC's.
 4. A unit according to claim 3, in which said light emitting meansand said driving means are packaged as one circuit element.
 5. A unitaccording to claim 3, in which said flexible electrically insulatingcircuit support means is made of a flexible solid organic resin.
 6. Aunit according to claim 5, in which said photo-sensing means and saidlight emitting means are mounted at a position on said flexiblesupporting means close to each other.
 7. A unit according to claim 6,which further comprises light shielding means to prevent the displayinformation light beam from said light emitting means from impinging onsaid photo-sensing means; said shielding means being located between thepath of light from said light emitting means and the light path to saidphoto-sensing means.
 8. A unit according to claim 7, in which said viewfinder optical means includes:first optical means adapted to have atleast a portion of the object light beam impinge on said photo-sensingmeans, and second optical means adapted to introduce the displayinformation light beam from said light emitting means, wherein, saidphoto-sensing means is positioned close to said first optical means, andsaid light emitting means is positioned close to said second opticalmeans, and said light shielding means is positioned between said firstoptical means and said second optical means.
 9. A unit according toclaim 1, in which said electrically insulating flexible circuit meanshas:first portion to be housed in the above mentioned restricted spacenear the aperture frame means, and second portion to be bent relative tosaid first portion and housed in a restricted space at the bottom ofsaid camera, the opening of the flexible supporting means being formedinside said first portion, said photo-sensing means and at least a partof said display means being positioned at said first portion, saidexposure operation circuit means being positioned at said secondportion.
 10. A unit according to claim 1, in which said exposureoperation circuit means determines a proper exposure time based on theoutput signal from said photo-sensing means, while said display meansdisplays the proper exposure time information in response to the outputsignal from the exposure operation circuit means.
 11. A printed circuitunit for a camera which is provided with:a photo-taking lens system,view finder optical means, aperture frame means to define a photographicpicture frame, and setting means to electrically set one or moreexposure factors, wherein said printed circuit unit comprises:(A)photo-taking means to measure the brightness of an object to bephotographed by said camera, said sensing means producing an electricsignal corresponding to the object brightness, (B) exposure operationcircuit means to determine a proper exposure value based on the outputsignal from said photosensing means and the exposure factors provided bysaid setting means; said exposure operation circuit means producing anelectric signal corresponding to the proper exposure value,(C) displaymeans to electro-optically display one or more exposure valueinformations, (D) electrically insulating flexible circuit supportingmeans adapted to be bent into a configuration which fits in a desiredshape within said camera and having an opening at least equal to thesize of said picture frame defined by said aperture frame means, and (E)electrical conductive means to provide electric connection among saidphoto-sensing means, said exposure operation circuit means, said displaymeans and said setting means; said conductive means being mounted onsaid flexible supporting means, said photo-sensing means, said exposureoperation circuit means and said display means being carried on saidflexible supporting means and being electrically connected to saidconductive means, and said flexible supporting means being constructedso that said photo-sensing means is positioned to be albe to receive alight beam from said object through at least a part of said view finderoptical means, also said display means positioned for having the displayinformation light beam displaying said proper exposure value informationimpinge on at least a part of said view finder optical means, further,said opening of the supporting means matches said photographing pictureframe defined by said aperture frame means, and is mounted in saidcamera utilizing a restricted space near said aperture frame means. 12.A unit according to claim 11, in which said setting means includes:firstelectric means to provide film sensitivity information to said exposureoperation circuit means, and second electric means to provide a presetexposure aperture value information to said exposure operation circuitmeans, said exposure operation circuit means being electricallyconnected to said first and second electric means through saidconductive means carried on said flexible supporting means anddetermining a proper exposure time value based on the film sensitivityinformation provided by said first electric means, and the presetexposure aperture value information provided by said second electricmeans as well as the object brightness information provided by saidphoto-sensing means, display means electro-optically displaying theproper exposure time value information based on the output signal fromsaid exposure operation circuit means.
 13. A unit according to claim 12,in which said display means is electrically connected to said secondelectric means through said conductive means carried on the supportingmeans and electro-optically displays and preset exposure aperture valueinformation based on the electric signal from said second electricmeans, together with said proper exposure time value information.
 14. Aunit according to claim 11, in which said display means includes:lightemitting means to digitally display the proper exposure valueinformation, digital conversion circuit means to convert the outputsignal from said exposure operation circuit means into a digital signal,said converting circuit means being electrically connected to saidexposure operation circuit means through said conductive means carriedon said flexible supporting means, and driving circuit means toelectrically drive said light emitting means based on the digital signalproduced by said digital conversion circuit means, said driving circuitmeans being electrically connected to said light emitting means and saiddigital conversion circuit means.
 15. A unit according to claim 14, inwhich said digital conversion circuit means and said driving circuitmeans are respective integrated circuit chips, and said exposureoperation circuit means includes integrated circuits.
 16. A unitaccording to claim 15, in which said light emitting means and saiddriving means are packaged as a single circuit element.
 17. A unitaccording to claim 14, in which said flexible electrically insulatingcircuit support means is made of a flexible solid organic resin.
 18. Aunit according to claim 28, in which said photo-sensing means and saidlight emitting means are mounted close to each other on said flexiblesupporting means.
 19. A unit according to claim 18, which furthercomprises a light shielding means to prevent the display informationlight beam from said light emitting means from impinging onto saidphoto-sensing means; said shielding means being located between thedisplay light path of said light emitting means and the photo-sensinglight path of said photo-sensing means.
 20. A unit according to claim19, in which said view finder optical means includes:first optical meansadapted to have at least a portion of the object light beam impinge onsaid photo-sensing means, and second optical means adapted to introducethe display information light beam from said light emitting means, saidphoto-sensing means being positioned close to said first optical means,and said light emitting means being positioned close to said secondoptical means, and said light shielding means being positioned betweensaid first optical means and said second optical means.
 21. A unitaccording to claim 11, in which said electrically insulating flexiblecircuit means has:a first portion to be housed in the restricted spacenear the aperture frame means, and a second portion to be bent againstsaid first portion and housed in a restricted space at the bottom ofsaid camera, the above mentioned opening of the flexible supportingmeans being formed at inside of said first portion, and saidphoto-sensing means and at least a part of said display means beingpositioned at said first portion, said exposure operation circuit meansbeing positioned at said second portion.
 22. A printed circuit unit fora finder adapter which is dismountable from a camera body and isprovided with:view finder optical means, and a housing to house saidoptical means, having an opening to make an object to be photographedobservable through said optical means, wherein said printed circuit unitcomprises:(A) photo-sensing means to measure the brightness of an objectand producing an electric output signal corresponding to the objectbrightness, (B) exposure operation circuit means to determine a properexposure value based on the output signal of said photo-sensing means;said circuit means producing an electric output signal corresponding tothe proper exposure value, (C) display means to electro-opticallydisplay the proper exposure value information on the basis of the outputsignal from said exposure operation circuit means, (D) electricallyinsulating flexible circuit supporting means adapted to be bent into aconfiguration so as to fit in a desired space within said housing, andhaving one cut-out part corresponding to said opening of the housing,(E) electrically conductive means carried on said flexible supportingmeans, said photo-sensing means as well as said exposure operationcircuit means and said display means being carried on said flexiblesupporting means, and said photo-sensing means and said display meansbeing electrically connected to said exposure operation circuit meansthrough said electrically conductive means, and (F) terminal meansadapted to provide electric connection between said conductive means andsaid camera body; said terminal means being electrically connected tosaid conductive means and sticking out of said housing, said flexiblesupporting means being constructed so that: said photo-sensing means isplaced to be able to receive a portion of a light beam from said objectthrough at least a part of said view finder optical means, said displaymeans is placed to be able to have the display information light beam todisplay said proper exposure value information impinge on at least apart of said view finder optical means, said cut-out part corresponds tosaid opening of the housing, and is mounted in a camera utilizing arestricted space within said housing.
 23. A unit according to claim 22,in which said display means includes:light emitting means to digitallydisplay the proper exposure value information, digital conversioncircuit means to convert the output signal from said exposure operationcircuit means into digital signal, said converting circuit means beingelectrically connected to said exposure operation circuit means throughsaid conductive means carried on said flexible supporting means, anddriving circuit means to electrically drive said light emitting means onthe basis of the digital signal produced by said digital conversioncircuit means, said driving circuit means being electrically connectedto said light emitting means and said digital conversion circuit means.24. A unit according to claim 23, in which said digital conversioncircuit means and said driving circuit means are respective integratedcircuit chips, and said exposure operation circuit means includesintegrated circuits.
 25. A unit according to claim 24, in which saidelectrically insulating flexible supporting means is formed with aflexible solid organic resin.
 26. A unit according to claim 25, in whichsaid photo-sensing means is mounted on a plate portion of the supportingmeans where said cut-out part is formed, and is positioned between saidoptical means and said housing together with said cut-out part so as tobe able to receive a portion of a light beam passing from said viewfinder optical means toward said opening of the housing.
 27. A unitaccording to claim 26, in which said photo-sensing means includes twophoto-sensing elements, which are mounted on said plate portion of thesupporting means for sandwiching said cut-out part.
 28. A printedcircuit unit for a finder adapter which may be dismounted from a singlelens reflex camera body setting means for electrically setting one ormore exposure factors, and is provided with;view finder optical means tomake an image of an ob ject to be photographed observable, and a housingwhich houses said optical means and has an opening to make object imageobservable through said optical means, wherein said printed circuit unitcomprises:(A) a photo-sensing means to measure the brightness of anobject to produce an electric signal corresponding to the objectbrightness, (B) an exposure operation circuit means to determine aproper exposure value based on the output signal from said photo-sensingmeans and the exposure factor of said setting means, and to produce anelectric signal as corresponding to the proper exposure value, (C) adisplay means to electro-optically display one or more exposure valueinformations, (D) electrically insulating flexible circuit supportingmeans adapted to be bent into a configuration so as to fit in a desiredspace within said housing and having one cut-out part corresponding tosaid opening of the housing, (E) electrically conductive means forelectric connection of said photo-sensitive means, said exposureoperation circuit means and said display means, wherein saidelectrically conductive means is carried on said flexible supportingmeans, and said photo-sensing means, said exposure operation circuitmeans and said display means are carried on said flexible supportingmeans and electrically connected to said conductive means, and (F) aterminal to provide electric connection between said conductive meansand said setting means, and is electrically connected to said conductivemeans so as to stick out of said housing, said flexible supporting meansbeing mounted in a camera utilizing a restricted space within saidhousing in such manner that: said photo-sensing means is placed at aposition to be able to receive alight beam from said object through atleast a part of said view finder optical means, said display means isplaced at a position having the display information light beam fordisplaying said proper exposure value information impinge on at least apart of said view finder optical means, and said cut-out partcorresponds to said opening of the housing.
 29. A unit according toclaim 28, in which said setting means includes:first electric means forproviding film sensitivity information to said exposure operationcircuit means, and second electric means for providing a preset exposureaperture value information to said exposure operation circuit means,said exposure operation circuit means being electrically connected tosaid first and second electric means through said coductive meanscarried on said flexible supporting means and determining a properexposure time value based on the film sensitivity information from saidfirst electric means and the preset exposure aperture value informationgiven by said second electric means as well as the object brightnessinformation given by said photo-sensing means, and said display meanselectro-optically displaying the proper exposure time value informationbased on the output signal from said exposure operation circuit means.30. A unit according to claim 29, in which said display means is alsoelectrically connected to said second electric means through saidconductive means carried on the supporting means and electro-opticallydisplay the preset exposure aperture value information based on theelectric signal given by said second electric means and said properexposure time value information.
 31. A unit according to claim 28, inwhich said display means includes:light emitting means to digitallydisplay the proper exposure value information, digital conversioncircuit means to convert the output signal from said exposure operationcircuit means into a digital signal, said converting circuit means beingelectrically connected to said exposure operation circuit means throughsaid conductive means carried on said flexible supporting means, anddriving circuit means to electrically drive said light emitting meansbased on the digital signal produced from said digital conversioncircuit means, said driving circuit means being electrically connectedto said light emitting means and said digital conversion circuit means.32. A unit according to claim 31, in which said digital conversioncircuit means and said driving circuit means are respective integratedcircuit chips, and said exposure operation circuit means includesintegrated circuits.
 33. A unit according to claim 32, in which saidelectrically insulating flexible supporting means is formed with aflexible solid organic resin.
 34. A unit according to claim 33, in whichsaid photog-sensing means is mounted on a plate portion of thesupporting means where said cut-out part is formed, and is positionedbetween said optical means and said housing together with said cut-outpart so as to be able to receive a portion of a light beam being passingfrom said view finder optical means toward said opening of the housing.35. A unit according to claim 34, in which said photo-sensing meansincludes two photo-sensing elements mounted on said plate portion of thesupporting means for sandwiching said cut-out part.